


Swing and a miss

by corsica



Category: Fate/Grand Order
Genre: F/M, castor being a siscon as per usual, inspired by santa karna's voice line for the dioscuri
Language: English
Status: Completed
Published: 2020-12-28
Updated: 2020-12-28
Packaged: 2021-03-10 19:41:47
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,352
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28392573
Author URL: https://archiveofourown.org/users/corsica/pseuds/corsica
Summary: Castor misreads a situation and Karna, unfortunately, is the one who has to explain things to him.
Relationships: Female Fujimaru Ritsuka/Karna | Lancer, Fujimaru Ritsuka/Karna | Lancer of Red
Comments: 11
Kudos: 29





	Swing and a miss

**Author's Note:**

> christmas may be over but santa karna is eternal
> 
> [also inspired by this post](https://tainbocuailnge.tumblr.com/post/170130188667/karna-at-every-possible-turn-i-love-you-i)

…

He cannot find Pollux anywhere.

She rarely strays from his side, and Castor is storming through the halls of Chaldea as he tries to find her. Servants wisely move out of his way as he makes his war path; the lack of his sister by his side is even enough for most people to turn tail the second they see him.

The longer he goes on, the more desperate his thoughts become.

 _'She could be injured...'_ chills run down his spine, _'Or worse...!'_

But as he rounds a corner, he sees Pollux holding a towel around her neck, speaking to their Master, and—.

Castor's eyes widen, and his nostrils flare.

_And another male Servant._

It is not _only_ another _male Servant,_ but one who is of similar caliber to his own sister, with an even higher level of Divinity. He is from India, Castor's memory tells him, and it is a strain but he remembers that his name is Karna. Though Castor has never spoken to Karna personally (really, who does he speak to besides Pollux and, when prodded, Ritsuka), Castor is aware of just how powerful he is.

…

Powerful in spite of the strange outfit he's wearing. Has he always worn that...? He feels like he would remember the thigh high boots.

Castor shakes his head. It doesn't matter. He _must_ get his sister away from that man at _all costs._

“Sister!” he shouts down towards the trio, “What are you doing? Where have you been?!”

“Oh, Castor,” she begins with a smile, “You were sleeping so soundly, I did not want to wake you, so—.”

She's cut off as he puts his hands on her shoulders and brings her away from the other two, and he stares furiously at Karna.

“You are attempting to court my sister, aren't you?!” he scoffs, and the cheer on Pollux's face shifts to pain, while Ritsuka can only muster up exasperation as she pinches the bridge of her nose.

Karna, however, blinks, confused from being so aggressively accosted, “...No, I...” he takes his hood down from his head and regards Pollux solemnly, “...I'm sorry, I didn't mean to give you that impression.”

Pollux's exhausted “you _didn't”_ is drowned out by Castor, “Don't _lie!_ It's clear that you want to bed her!”

 _“Brother,”_ Pollux growls through gritted teeth, “I woke earlier than you did, and I did not wish to wake you, as you were sleeping so peacefully. We ran into each other in the hallway and he said he wished to go against me in a friendly, impromptu boxing match, and Master was interested in watching.”

“Friendly? _Hardly._ That is what he _wants_ you to think, Pollux,” he tuts, “But the unbridled lust he has for you is plain for anyone to see.”

Ritsuka has to fake a coughing fit to hide her laughter.

Karna waits for an “I'm okay” from Ritsuka before he starts to address Castor again, and the confusion on his face has only deepened in the time since, “Your sister is an excellent boxer, and there is much I could learn from her, but I'm not trying to court her...I am not sure what it is I can do or say that would convince you.”

Castor stares at him with narrowed eyes, carefully analyzing him. It is a long few minutes of silence, but Castor's eyes widen, and he is visibly taken aback when he realizes that Karna is actually telling the truth and does not, in fact, want to sleep with Pollux.

“Wh—.”

“Do you finally understand?” Pollux sighs, “Honestly...”

“Wh— _That's ridiculous!”_

“Castor—?”

He guffaws, completely incredulous, _“Look at her!_ Pollux is powerful, attractive, talented— _what kind of man are you?!_ Is poor eyesight part of your heroic legend? How could you _not_ desire her?!”

Pollux's eyes grow wider and wider in mortification and her cheeks are burning scarlet as she gapes at her brother in disbelief, _“Castor—!”_

“She is more than good enough for you—she is _better_ than you—I _demand_ that you have feelings for her!”

Karna's mouth sets into a thin line and his expression turns troubled. There is a short period of silence as Karna tips his head down, eyes closed, deep in thought. Castor is somehow both enraged and expectant as he stares at Karna, waiting for an answer; he does not notice Ritsuka mouthing _“I'm really sorry”_ to Pollux, nor Pollux's head shake and shoulder slump response.

“I apologize, but,” Karna finally speaks, and his eyes open as he directs a sympathetic look towards Castor, “How do I put this...that's not something I'm able to do. I can't say anything bad about Pollux at all. In fact, I would like to spar with her again sometime. But I cannot see her like that...I already have feelings for Ritsuka.”

There's a beat as Castor digests the information.

“...What?”

“Yeah, I mean, we've been holding hands through this whole conversation,” Ritsuka says, and Karna nods as she holds up their joined hands to punctuate the point, “You...really didn't notice?”

Pollux clenches her fists, glaring daggers at him, and gestures towards them in a way that says _“see?!”._ Castor opens his mouth to retort, but the daggers Pollux is glaring at her brother turn into zweihanders, and he finally has the decency to be a little embarrassed.

“We've been involved for quite some time now, but if there are still people that don't notice...” he glances down at Ritsuka, who responds with a curious tilt of her head.

“What is it?”

Karna sighs.

“...I see. Ritsuka, it seems that I still haven't been forthcoming enough with how deeply I feel for you. I thought I'd been improving, too...Allow me to fix this.”

Ritsuka's face starts to heat up, and she holds her hands up as Karna turns to fully face her, putting his hands on her shoulders as the look in his eyes turns soft, “N-No! That's not—Karna, you're _fine—.”_

“It's my fault this started in the first place...I still haven't spoken enough about how incredible you are. The luck I have, to be summoned by you...”

“Karna—.”

“I never deserved a Master as caring as you, who gives someone like me so much more than what they're worth...but you repeatedly go above and beyond for me in ways I could never imagine. You've given me feelings of happiness that I will never be able to forget. I don't know what I did to earn it, but the trust and affection I receive from you couldn't make me more blessed as a Servant, and though I may be the Son of Surya, _you_ are the light of my life.”

_“Karna—.”_

“Ritsuka...I don't know if I'm communicating this well enough, but I love you—.”

She slaps her hands over his mouth. Face, ears, neck—her entire _body_ may as well have been flushing.

“Th—Thank you, Karna, you've made yourself perfectly clear,” she pauses for a moment and averts her eyes away before speaking in a mumble, “I love you, too...”

Pollux is still glaring at her brother, who is wrinkling his nose at the affectionate display in front of him.

“I believe you may be the only person in this entire _facility_ who did not know about the two of them. They have never been very subtle.”

Castor huffs and crosses his arms, “Well, let me say this then: I would not be surprised if every man that has ever laid eyes on you found you to be the most radiant woman in the world. I must protect you, Pollux,” he pauses to eye Ritsuka up and down, “...And the Hero of Charity's tastes are somewhat questionable in the first place.”

“I could say the same for _you,_ brother.”

“We may have a contract with her, but...” Castor gestures towards her, and Ritsuka blinks owlishly and points to herself, “How could he pick her over you?! Look at her! Her breasts are not _nearly_ as nice as yours—.”

He is hit square in the face by Pollux's fist, and Castor falls to the ground, unconscious.


End file.
